Magnetic alloy

ABSTRACT

A MAGNETIC ALLOY CHARACTERIZED BY HIGH PERMEABILITY AT LOW FLUX DENSITY AND COMPRISING, AS EXPRESSED IN PERCENT BY WEIGHT:   NICKEL 79-81 MANGANESE 0.25-0.75 SILICON 0.10-0.20 TITANIUM 0.05-0.15 IRON BALANCE   OLYBDENUM 4.25-5.25

United States Patent 3,723,106 MAGNETIC ALLOY Juergen Schlenker, Parsippany, and Teh P0 Wang, Cedar Grove, N.J., assigmors to Wilbur B. Driver Co. No Drawing. Filed May 23, 1969, Ser. No. 827,180 Int. Cl. C22c 19/00 US. Cl. 75-170 3 Claims ABSTRACT OF THE DISCLOSURE A magnetic alloy characterized by high permeability at low flux density and comprising, as expressed in percent by weight:

Molybdenum 4.25-5.25 Nickel 79-81 Manganese 0.25-0.75 Silicon 0.10-0.20

Titanium 0.05-0.15 Iron Balance BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION We have discovered that the additions of small amounts of silicon and titanium to our conventional moly-permalloy compositions results in substantially increased values of initial permeability.

In accordance with our invention, our magnetic alloy comprises, as expressed in percent by weight:

Nickel 79-81 Molybdenum 4.25-5.25 Manganese 0.25-0.75 Silicon 0.10-0.20 Titanium 0.05-0.15 Iron Balance DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS One alloy composition in accordance with our invention is as follows:

Percent Nickel 79.66 Molybdenum 4.95 Manganese 0.63 Silicon 0.14 Sulfur 0.001 Titanium 0.10 Carbon -0003 Iron Balance An ingot of the above composition was fabricated by conventional techniques and processed into 0.006 inch thick strip. Another ingot lacking silicon and titanium 3,723,106 Patented Mar. 27, 1973 lCe but otherwise identical in composition was fabricated and processed in the same manner. This second composition is known and used by us. Samples from both strips were heated for four hours at 2150 F. in a hydrogen atmosphere. Thereafter, samples of both strips were subjected to a three-stage cooling process. The first stage utilizes the temperature range 2150 F. to 1100 F; the second stage, the temperature range 1100 F.; and the third stage, the temperature range 600 F. to room temperature. The rates of cooling the first and third stages are not critical and do not influence initial permeability. The critical stage for cooling is the second stage which employs the temperature range of 1100 F. to 600 F. in which an ordering transformation occurs. Experimentally, we have determined that a rate of cooling of 375 F. per hour was optimum in this second stage and accordingly employed this rate in this second stage.

Four samples of each alloy composition were heat treated simultaneously in the same manner. The samples of our new alloy composition were found to have an average initial permeability, at forty gausses, of seventy two thousand gausses per oersted at a flux density of forty gausses. The samples of the known alloy composition were found to have an average initial permeability of forty thousand gausses per oersted at a flux density of forty gausses.

The magnetic characteristics outlined above can be maintained when the various constituents other than carbon and sulfur are maintained within the limits indicated. Carbon and sulphur are tramp elements and do not contribute by their presence to the characteristics desired. Indeed, excess quantities of carbon and sulfur can result in impaired magnetic properties. Thus the carbon content must not exceed 0.01% and the sulfur content must not exceed 0.005%.

What is claimed is:

1. A magnetic alloy characterized by high permeability at low flux density and consisting essentially of, as expressed in percent by weight:

Nickel 79-81 Molybdenum 4.25-5.25 Manganese 0.25-0.75 Silicon 0.10-0.20 Titanium 0.05-0.15 Iron Balance 2. An alloy as set forth in claim 1 having a specific composition as follows:

Percent Nickel 79.66 Molybdenum 4.95 Manganese 0.63 Silicon 0.14 Titanium 0.10 Iron Balance 3. An alloy as set forth in claim 1 which also can contain up to 0.01% carbon and up to 0.005% sulfur.

References Cited UNITED STATES PATENTS 3,269,834 8/1966 Lykens et a1. 170

RICHARD O. DEAN, Primary Examiner US. Cl. X.R. 148-31.55 

